1. Field of the Invention
The present invention relates to an endoscope operation mechanism equipped with a bending operation portion for performing an operation to bend a bending portion provided in an insertion portion of an endoscope, and an endoscope.
2. Description of the Related Art
In order to perform, for example, observation and treatment of a lesion inside a subject, an endoscope conventionally includes an insertion portion having flexibility that is inserted into the subject, and an operation apparatus that performs operations for bending the insertion portion in the UD (upward/downward) direction and the RL (right/left) direction.
In such an endoscope, the operation apparatus is provided with a UD angle knob configured to perform operations in the UD direction and an RL angle knob configured to perform operations in the RL direction.
When an operator of the endoscope performs observation and treatment of a lesion or the like, the operator operates the UD angle knob and the RL angle knob to cause a bending portion that is provided in the insertion portion to bend in the UD direction and RL direction.
For example, International Publication No. WO2013/129494 discloses technology that improves the bending operability in the UD direction and the RL direction of an insertion portion in such an endoscope.
In International Publication No. WO2013/129494, an endoscope as an insertion apparatus is disclosed in which a knob is provided configured to perform upward/downward (UD) bending operations of the insertion portion, and an RL operation dial is arranged configured to bend the insertion portion in the right/left (RL) direction.
In the conventional endoscope, a rotational state of an RL operation dial that instructs a bending operation of an insertion portion by rotating an operation element for right/left (RL) direction bending within an arbitrary rotational angle range from 0 to ±90 degrees can be maintained to thereby maintain a bending state of a bending portion.
Further, with respect to the conventional endoscope, technology has been disclosed regarding a reversion function that, when the RL operation dial is rotated by an amount greater than the arbitrary rotational angle that was set, causes the RL operation dial to return to a position within the rotational angle range that includes an initial position (a neutral position of the RL dial).